Length-adjuster for pendulums.



W. J. EVANS. LENGTH ADJUSTER FOB PENDULUMS. APPLICATION nun ms. 21,1910.

1,071,61 1 Patented Aug. 26, 1913.

UNITED STATES WALTER J". EVANS, OF CHICAGO, ILLINOIS.

Specification of Letters Patent.

LENGTH-ADJUSTER FOR PENDULUMS.

Patented Aug. 26,1913.

Application filed larch 21, 1910. Serial No. 550,601.

To all whom it may concern Be it known that I, IYAL'IER J. EVANS, acitizen of the United States of America, and a resident of Chicago,county of Cook, and State of Illinois, have invented certain new anduseful Improvements in Length-Adjusters for Pendulums, of which thefollowing is a specification.

My invention relates to pendulums for clocks, and has for its objectimprovements in devices for adjusting the lengths of the pendulum so asto regulate the clock.

In the accompanying drawings Figure 1 is a front elevation of the bob ofa Pendulum with a part of the rod upon which it is suspended; Fig. 2 isa vertical central section of the same; Fig. 3 is a partial rearelevation, and Fig. it is a section showing the cocentric used for smalladjustments.

In the said drawings, the rod is represented by B and the bob by B. Inthe center of the bob is a pin C which goes through an eccentric sleeveE, which sleeve is in a bearing in the bob B. On the rear end of the pinC is a cam D held in place by a nut F. The cam D engages a pin P on therod B. On the front end of the pin C- is an arm A secured thereto, andby means of which the cam may be adjusted. The arm A is of flexible andresilient material, or, in other words, it is a spring arm. The outerend of said arm has a pin on its inner face, which is adapted to engagein any one of aseries of holes in a scale marked S, shown at the upperpart of Fig. 1. This scale is graduated opposite each of the holes andthis scale indicates the position at which the arm A is held, andconsequently the position of the cam D in its engagement upon the )in P.By moving the arm A either to the right or left the cam D is moved onthe pin P so as to raise or lower the bob B onthe rod It. Thegraduations on the'scale S are so related to the movement produced bythe cam that the graduations indicate the change in the length of thependulum as measured in time as minutes for a longer unit of time as aday. Thus when the arm A is located at the zero point at the center ofthe scale if the clock is running one minute a day too slow the arm maybe moved to the right over to the graduation marked 1 the effect ofwhich will be to shorten the pendulum enough to make the clock run oneminute faster in one day. If the clock needs more than one minute ofadjustment, then the arm A will be advanced correspondingly. Thegraduation shown represents graduations amounting to variations ofone-quarter of a minute per day, the word Day being placed adjacent tothis scale to indicate the amount of adjustments that are producedthereon. The sleeve E is secured to another arm A which is adapted tosweep over another scale S As this sleeve E is in the form of aneccentric the movement of the arm A will raise or lower the pin C in thebob B, the effect of which would be to change the osition of the bobwith respect to the pin g upon which the cam D rests. As a consequenceof this construction, the eccentric sleeve E is a second means ofadjusting the pendulum length. The adjustments made by the eccentric Eare much smaller than those made by the cam D, and the amount ofadjustment made by moving the arm A is determined by graduations on thescale S As indicated in the drawings, these graduations are in minutesper week. Thus assuming that the arm A is in the posit-ion shown in thedrawings, then if the clock should run one-fourth of a minute too slow amovement of the arm A from the position in which it now is so that thepin thereon should engage the next adjacent hole the efiect of theadjustment would be to shorten the pendulum sufficiently to make theclock run one-fourth of minute faster than the week before. The arm A isalso a spring arm and has a pin thereon to engage holes in the scale SIt will be evident from the previous description that there are two waysof adjusting the length of the pendulum, either of which will serve tolengthen or shorten the pendulum producing the corresponding result ofmaking the clock run slower or faster according to which adjustment ismade. Also that one of these adjustments is a comparatively coarseadjustment consisting of changes of minutes and fractions of a minute ina day of time. The other adjustment is a comparatively fine adjustmentconsisting of regulating the clock by changing its speed in minutes orfractions of a minute in a week of time. It will also be obvious that aunit of time may be other than that of a day or week, and in cases ofextremely fine adjustments the adjustments may be fractions of a minutein a period of a month of time.

While I have shown my device as mounted upon a bob of a pendulum, and Igenerally prefer to use it in that way, it will be quite evident that Imight apply the same compound adjustment at the upper end of thependulum and thereby raise or lower the pendulum as necessity requires.

Instead of making the scale of adjustments on the arcs over which thearms A and A move, I may, if I choose, place a scale on the pendulum rodR as shown at S and add a small pointer S to the bob for indicating therise and fall. of the bob by moving either the arm A or A This scaleplaced in this way may be graduated with any degree of fineness and may,for convenience, be marked to represent the inches in length of thetheoretical pendulum, or may be marked in any other manner for thepurpose desired. The numbering of this scale is not shown, as in thiscase it will depend upon what particular kind of numbering is desired.lVhen used in connection with the registering scales S and S it willprobably be convenient to number them in inches of the length of thependulum, but when used without the other scales it may be made torepresent variations in minutes or fractions of a minute in a unit oftime as a day.

What I claim is:

1. In an adjustment for pendulum lengths, the combination of twoindependently acting devices on the same axis for raising and lowering abob, and a lockable registering device for indicating the amount ofadjustment of the bob so made in minutes or frac tions thereof in a unitperiod of time as a day or week.

2. An adjustment for pendulum lengths consisting of two parts on acommon center, one part of which serves in making relatively largeadjustments, and the other part which serves in making relatively smalladjustments, and devices for indicating the amount of each adjustment.

3. An adjustment for pendulum lengths consisting of two parts on thesame center, one part for coarse adjustments and the other part for fineadjustments, registers for indicating the amount of adjustment of eachpart, and devices for securing the adjustments thus made.

4. In anadjustment for pendulum lengths, a device for raising andlowering a pendulum bob, a register for indicating the amount ofmovement in time per day, and a second adjusting device on the samecenter and acting independently of the first named device, and aregister for indicating the amount of movement by the last named devicein time per week.

5. An adjustment for pendulum length, consisting of a bob with coarseand fine adjusting means 011 the same axis.

6. The combination with the rod and bob of a pendulum, of twoindependently operable devices on the bob for adjusting same on the rod,said devices being arranged for producing coarse and fine adjustments,an independent arm for each device, and a graduated scale for each arm.

7. The combination with a pendulum and two independently operabledevices located to move about a common center for adjusting its lengthso as to vary the time of its movement, of a registering scale forindicating the amount of such adjustments, said scale being so graduatedas to indicate the adjustments in fractions of a minute in some unit oftime.

8. In a pendulum adjustment, a cam for adjusting the length of thependulum, an arm by which said cam is moved, an eccentric for makingsmall adjustments in the position of said cam independently of said arm,and a second arm by which said eccentric is moved.

9. In a pendulum adjustment, a cam for coarse adjustments, an eccentricfor fine adjust-ments, and a pair of flexible and resilient self-lockingarms by which said cam and eccentric are independently adjusted.

10. In a pendulum adjustment a cam for making. coarse adjustments of thebob of the pendulum, an eccentric for making fine adjustments of the bobof the pendulum, a pair of independently operable flexible and resilientarms by which said cam and eccentric are moved, and a scale forindicating the amount of adjustment, said scale and arm being arrangedto engage each other by the resilient action of the arm to hold said armat its adjustment.

Signed at Chicago, Ill. this 19th day of March 1910.

lVALTER J EVANS. lVitnesses:

C. L. REDFIELD, WVALTER H. REDFIELD.

Gopies of this patent may be obtained for five cents each, by addressingthe Commissioner of latents.

Washington, D. C.

